Casting and method of producing the same



A fil 20, 1926. 1,581,790

J. c. DAVIS CASTING AND METHOD OF PRODUCING THE SAME Filed Nov. 15, 19222' Sheets-Sheet 1 A ril 20 1926., 1,581,790

'J. C. DAVIS CASTING AND METHOD OF PRODUCING THE SAME Filed Nov. 15.1922 2 Sheets-Sheet 2 36 l 35 .I "I .29

55 I2 34 I0 9 "IE.

.In III] lgn E] 25 F4 1;l= v w m 25/30 $31 [nae/12%;"

, I 26 fig?? Patented Apr. 20, 1926.

UNITED STATES PATENT OFFICE.

. JAMES CAREY DAVIS, OF HINSDALE, ILLINOIS.

CASTING AND METHOD OF PRODUCING THE SAME.

Application filed Noveinberlti, 1922. Serial No. 600,65G.

1 of casting metal, and to improve means and methods for producingcastings which are not only smooth and clean in that they are free frompits or holes and from entrained dirt-such as sand, but are notablydense as well as solid.

Pits, holes, dirt, and the like involve roughness, flaking. shelllng,and a consequent cutting action, since they 'cannot readily be machinedout, and other obvious imperfections with an incident intolerably "greatmanufacturing cost due to the high scrap loss of the castingsnecessarily discarded on account of inavailability for the purposescontemplated.

It will be appreciated that castings of high quality, the attainment ofwhich is one of my present objectives, are useful for many purposes, butare not only of utility but practically essential for a number of uses,such for'example as car-wheels and other structures more. or lessanalogous in certain characteristics.

The case of car-wheels is an example for which the invention ispeculiarly adaptable, inasmuch as where desirable, additionally ahardening or other modifying element may be so introduced at such aplace and stage and so regulated and determined, and with such degree ofnicety as may be desired,

that not only a solidity but of metal throughout the casting, or certainparts thereof, may be secured but also that the repeated production of arun of castings of like composition and density may be attained.

The castings produced by my present improvements may be of uniformcomposition throughout, or the introduction of a modifying clementreferred to may be effected when, if and as desired, thus in the furnaceor cupola, in the ladle, or between the ladle,

and the mold, whereby the casting may be of differing composition indifferentparts.

For the purpose of illustration of the present invention in its variousaspects, I have therefore found it convenient in the present alsohomogeneity specification and drawings to refer to it in' connectionwith its adaptability for carwheels and the like, which may be ofuniform or variable composition, according to the service in View.

In the production of such castings by other means and methods known tome I have heretofore experienced great difficulty not only in accuratelyapportioning the modifying element when desired butin attaining therequisite-solidity and density in the castings and in insuring aconstant runof castings which are both of the composition, solidity anddensity sought for,but at the same time free from insuperable peripheralimperfections such as foreign matter,

shelling, irregularities of contour, -etc.,-

which are intrinsic and more than merely superficial and so involveactual rejection ofthe product.

The principal objects of my present invention therefore involve theprovision of. an improved casting apparatus adapted for the inclusion ofmeans for the production of castingsof quite. perfect solidity and greatdensity; the provision of such an apparatus characterized bythe'inclusion of means whereby such density may be intensified atpredetermined localities; the provision of such an apparatus adaptedfor. the production of castings of varylng density, or varying both indensity and com position; the provision of a casting apparatuscharacterized by the employment of an auxiliary source of molten metalfor imparting solidity and high density to the casting; the provision ofa casting apparatus including arotating mold for such purpose; theprovision of an improved mold having means for receiving an ancillarysource of molten metal, one wherein such ancillary source may be drawnupon to compensate for shrinkage in the casting as it cools or entrainedgases are expelled from the casting or from the mold, and one adapted tofacilitate the escape of gas from the mold cavity; the production of acasting char? acterized by predetermined variation in its density; theprovision of such a casting fur-' predetermined varia-' which differs inkind as Well as degree from 7 those hitherto known.

The principal obj'ectsof my presentinvention furthercontempla-te theutilization of an improved method of making castings, which are ofvarying density in difi'erent portions, and, when if and as desired ofdifiering degrees of hardness in difi'erent portions, together withcertain other objects which will be hereinafter disclosed.

In the attainment of the objects andadvantages above noted, in theavoidance of the objections and disadvantages mentioned, and inaccomplishing certain ends and gaining certain benefits which will belowbe pointed out or clearly appear,'I have provided the constructionsillustrated in the accompanying drawings which for purposes ofconvenience as before suggested are adapted for the production of acar-wheel such as one made of steel which is solid, dense, hard andresistant and consequently of excellent wearing qualities at theperipheral ortread portion, and may be relatively softer toward thecenter and thereforemore tough andless apt to fracture.

In these drawings, it will beobserved that m-- Figure 1 I haveillustrated a mold provided with mean for rotating the same, and

a ladle for introducing molten metal into the mold, the mold beingprovided With ancillary means for supplying additional molten metal tothe casting proper as it shrinks, the mold and casting being shownincentral longitudinal section;

Figure 2 a plan view. of the mold of Figure 1;

Figure 3 a vi w of the casting therein produced;

Figure 4 an elevational view of a modified form of apparatus; and in.Figure 5 a paratus of Figure 4.

Referring first to the apparatus of Fig ures 1, 2 and 3, it will benoted that I may employ a mold, such as the car wheel mold '6, which ispreferably mounted upon a support 7 which is rotatable by means of asuitable drivlng mechanism indicated gening 10 for directin into themold molten metal from the lad e 11 or the like. 4 Interiorily the mold6 is provided with an ancillary receptacle for molten metal,

the excess of which will not form part of the finished. casting. In thecase of the production of such a casting as the car-wheel shown inFigure 3, I conveniently employ f two such receptacles which take theform of sinking heads 12, 12 in the cope 1.3 of the mold 6. In theresultant castings such remainder of the redundant metal from thesinking heads 12, '12, indicated at 12, 12,

are of course duly removed, before they are put into use.

plan view of part of the ap Referring now to the apparatus of Figures 4and 5, it-will be seenthat I here mount in a convenient place as in a itthe desired number of molds 6, each of which is mounted on a rotatabletable 7 driven by gearing 8.

For the purpose ofprovidin means whereby the molten metal from the ladle11 may be maintained at a height substantially uniform and will therebybe caused to descend in a solid column of uniform which comprises asupporting bed 22 carried upon axles 24 the wheels of which 25 arerevoluble thereupon and arranged to ride upon rails 26 the outer ends ofwhich are mounted upon trucks 27 and 28 which in turnride upon the rails29 and 30' oppositely disposed about the molds 6.

In carrying out my improved process of making castings, the modifyingelement, such as manganese may be added in the fur-- nace or cupola, orin the ladle 11, or between the ladle 11 and the mold 6, but for thepurpose of introducing and incorporating most perfectly and comminglingand distributing most thoroughly the modifying-element into le movedfrom one flask.

the stream of flowing metal 31, which as will be seen on reference toFigure 4 preferably takes the form substantially of a column withparallel sides, I may make use of an apparatus which here comprises avertical casing 32 for containing the modifying elements, such asmanganese, a lateral extension thereof 33, a nozzle 34 the ejector ofwhich, 35 is depressed somewhat fromthe horizontal, and a pipe 36connected to a source of air or other fluid pressure supply, andinserted into the apparatus below the casing 32 to the end that themodifying element may be drawn therefrom by fluid pressure and forcedinto the flowing stream of metal; In practice, I have found that thebest results are attained by the use of pressures between approximately50 and 125 lbs. per'square inch which will cause the modifying elementto penetrate the stream of molten metal, and that by flattening theejector 35 so that the spray of modifying material may be spread out toapproximately the diameter of the stream, and depressing the end of theejector so thatthe modifying material will strike the flowing stream inthe direc tion in which it flows, it will enter and be 'ouslyincorporated with the molten metal,

and will not have the tendency to become segregated in masses thereinnor to be unevenly disposed therein, nor to remain on the surface of thestream and subject to the action of the air.

For certain purposes it is highly desirable to attain an accurate anduniform proportioning of the quantities of the modifying element andmolten metal as they enter the mold. In order to do this, obviously itis not only desirable to have the modifying element delivered in uniformand unvarying quantity, but it is also desirable to have the moltenmetal delivered in uniform and -unvarying quantity. If the metal betaken .directly from a pouring ladle of the ordinary type its velocitywill vary as the height of the metal in the ladle varies. From this itfollows that if the rate. of flow of the modifying element be uniform,the proportion of the modifying element and metal delivered to the moldwill vary, because the rate of flow of the metal is not uniform. Inovercoming'this I have provided a choke device whereby I a m enabled tomaintain the height of the metal in that device substantially uniform.As a result, the discharge of metal into the mold is uniform.Furthermore, as thehead of metal in the choke device is relativelysmall, the issuing stream is in the form of a substantially solidcolumn. Furthermore, by emplo ing the injecting device referred to, themo ifying element is immediately embedded in and firmly held by theflowing metal, and is therefore uniformly carried into the mold.

In the production of a wheel of uniform composition I preferably employmolten steel having a specification of 0.25 to 0.50% carbon and-1.25 to2.0% manganese, which may be introduced in the furnace, though it Willbe understood my present improvements are available for'the productionof wheels having a yarying composition by graduating the addltion of themodifying material as canbe accomplished readily by introducing itbetween the ladle and the mold for example.

The molten metal is then poured into the.

mold 6 and as such mold fills the ancillar mold cavities are filled andthe sinking headz 12, 12 are formed.

The pouring'being finished, rotation of the mold is efiected until thecasting is solidified, whenitis removed from the mold and theexcrescenc-es 12312 are removed and the customary finishing operationsare performed. i

From experience I have ascertained that if the mold 6 remains stationaryI cannot infallibly attain the degree of solidity and density in thecastings, desired by me, but that utilizing a rotating mold at say 25 to100 R. P. M. centrifugal motion is imparted to the molten metal to suchan extent that the metal filling the sinking heads 12.

,12 servesto completely fill the outermost parts of the 'mold 6 in sucha manner that I am not only enabled to prevent the formation of holesand secure a solid and clean casting, but am enabled to attain inaddition to highly complete solidity a marked degree of density.

Inasmuch as I preferably make use of" centrifugal force the extent towhich the benefit thereof is attained obviously depends in part uponthe'rate of revolution imparted to the mold 6 and in part. the timeinterval through which such movement is con tinued.

, It is believed that the operation of my present invention and variousapplications of its use will be understood by those skilled in the artwithout further detailed description.

For certain purposes and in certain of its phases it may be employed inconnection v ing to the prospective uses of the castings produced. v y

In the claims Where I use the terms to preferentially densify, topreferentially compensate, to preferentially solidify, or topreferentially condense, I mean to include such property as would beobtained in rotary casting wherein an ancillary supply of molten metalis included as would favor the'addition of molten metal from theancillary supply to the periphery of the casting rather than to the bodyof the casting.

Having thus described my invention and illustrated its use What I claimas new and desireto secure by Letters Patent is:

1. The method of casting car wheels which includes introducing moltenmetal into a mold and then rotating the mold after pouring so as toimpart. centrifugal motion to the molten metalto force it outwardly tothe confines of the mold to an extent sufficient to densify the metal ofthe periphery of the casting.

2. The method of making car wheel castings which includes pouring moltenmetal into a mold including an ancillary chamber closed to theatmosphere and introducing metal in said chamber to provide an ancillarysupply of molten metal to preferentially compensate for rim shrinkage ofthe first mentioned metal as it cools.

3. The method of making car-wheel castings which includes incorporatingthrough a main pouring gate molten metal into a mold also including anancillary metal re- 1,

in said, means to. furnish an ancillary sup ply of metal and rotatingthemold to'impart centrifugal motion .of the first mentioned molten metaland'thereby draw into the -mold a supply of the last mentioned cry ofthe casting.

ings which includes incorporating molten metal into a mold including anancillar metal retaining means and introducing mo ten-"metal in saidmeans to furnishan ancillary supply of metal and rotating the mold as toimpart centrifugal motion to the first mentioned molten metal,-"and'thereby draw into the mold a supply of the lastmentionedm'oltenmetal to an extent sufficient to preferentially solidify *themetal of the periphery'ofthe casting; V 1

. 5. .The method of making castings which includes incorporating moltenmetal, into a mold including anancillary metal retaining means andintroducing molten metal'in said means to furnish an. ancillary supplyof metal and rotating'the mold to impart centrifugal motion-to the firstmentionedmolten metal and thereby draw into the mold a supply of'thelast mentioned molten metal to an extent sutli'cient to preferentiallysolidify the metal of the castin-gwith a, force characteristic of thecentrifugal force of substantially rimvelocity.

6. The method-of making castings which includes incorporating moltenmetal into a mold including an anclllary metal. retame ling means andintroducing molten metal in said means to furnish ancillary supply ofmetal and rotating the mold as toimpart centrifugal motion to the firstmentioned molten .metal, and thereby draw into the mold a supply of thelast mentioned molten metalto an extent-suflicient to preferentiallycondense and solidify the metal of the casting withfa forcecharacteristic of the cen-;

trifugal force of substantiallyrim velocity. 7. The methodof makingcar-wheel castingswhich includes introducing molten metal into a moldand an ancillary metal retaining means 'to-provide Jan ancillary supplyof molten metal,- and rotating the mold after it"is poured so as toimpart'c'entrifugal 'motionto the first mentioned -molten'me'tal,

and thereby draw into the mold a supply of the last-mentioned moltenmetaL;

8.- The method of making castings which includes'pouring into a mold amixture of fluid metal and amodifying element and r0 the mold after itis poured.

Wtatin .v

- 9.- The method of making car-wheel castings' which includespouring'into a mold a mixture of fluid metal and a modifying ele- .mentand rotating the mold after it is poureda-ta .rate of speed sufficientto condensethe outer portions of the metal.

' 4:. The method of making carwheel cast ti i tvedr. I

10. The method'of maliing car-wheel castpouring into a mold a aeletially. the same direction asthe flow thereof 7 between the'ladle andthe mold, and rotating the mold after it is oured.

ingsof varying composition and density which includes introducing into-amold a stream of metal in the form of substantially.

11-. The method of ma ing car-wheel castsupply of metal, and-rotatingthe mold after the casting is poured to force metal into the mold fromthe ancillary supply.

12. In a. casting apparatus, in combination with a source of moltenmetal,a nd a mol d, and means for rotating the same, a .limitedancillary source of molten metal for preferentially compensating forshrinkage in the casting after the pour from said first mentioned sourceis completed and as the mold is rotated. 13. In a rotary castingapparatus, provided with a pouring gate, and ancillary means closed toatmosphere for receiving a mold molten metal, from the main body ofmetal for the formation of a casting} therein.

provided with a pouring gate, and an ancillary sinkinghead closed toatmosphere for receiving molten metal for the formation of a castingthe-rein.

15. In a rotary casting apparatus, a car wheel mold provided with apouring gate,

and internal ancillary means for receivingmolten metal for the formationof a cast- "ing therein disposed near the periphery ofg the wheel.

16. In arotary casting apparatus, a car wheel mold provided with apouring ate,

and an interiorly disposed ancillary sin ing head closedto atmospherefor receiving molten, metal for the formation of a casting. thereindisposed near the periphery of POlIltS as produced by substantially com14, In a rotary casting apparatus, a mold letely pouring in a mold andthen rotating' the same.

18. "As a new car wheel-casting of predetermined uniform progressivevariation in density at difierent "points decreasing from the periphery.in-,

, wardly as produced by substantially comarticle of manufacture, a

pletely pouring in a mold and then rotating the same. 19. As a 'newarticle of manufacture, a

facture when the metal is fluid and the cast- 1 ing has been poured asproduced in a rotary mold including an internal ancillary supply 1 ofmolten metal intermediate the axis and the periphery of the casting.

20. As a new article of manufacture, a car wheel casting containing 0.25to 0.50% carbon and condensed during the course of manufacture when themetal is fluid and the casting has been poured as produced in a rotarymold including an internal ancillary supply of molten metal intermediatethe axis and the peripheryof the casting.

21. As a new article of manufacture, a car wheel casting containing 1.25to 2.0% manganese and condensed during the course of manufacture whenthemetal is fluid and the casting has been poured as rotary mold includingan internal ancillary supply of molten metal intermediate the axis andthe periphery of the casting.

22. As a new article of manufacture, a car wheel casting containing 0.25to 0.50% carbon, and 1.25 to 2.0% manganese and peripherally condensedduring the course of manufacture when the metal is fluid and the castinghas been poured. as produced in a rotary mold including an internalancillary supply of molten metal intermediate the axis and the peripheryof the casting.

23. A new article of manufacture, a car wheel castingcontaining 0.25 to0.50% carbon, and 1.25 to 2.0% manganese and condensed during the courseof manufacture by rotation of the mold when the metal is fluid and thecasting has been poured'as produced in a rotary mold including aninternal ancillary suppy of molten metal intermediate the axis and theperiphery of the'casting.

24. The method of making car wl1eelcastings which includes pouring intoa'mold amixture of fluid metal and a modifying .ele-

ment, the modifying element being introduced between the ladle and themold, in substantially the direction of the flow of the stream of moltenmetal, and rotating the mold after it is poured.

25. The method of making car wheel castings which includes pouring intoa'mold a mixture of'fluid metal and a modifying ele-- ment, themodifying element being forced into the stream of -molten metal insubstantially the same direction as the flow thereof:

between the ladle and the mold, and rotating the mold after it ispoured.

26. The method of manufacturing a car wheel casting, which comprisesintroducing molten metal into a mold; including an internal ancillarymeans ofretaining the molten metal located near the periphery of. thecasting and then rotating the mold for conproduced in a densing themolten metal at the outer portion of the casting.

ing, which comprises introducing molten metal together with a modifyingsubstance into .a mold including an internal ancillary means forretaining molten metal located 27. The method of manufacturing acastnear the periphery of the casting and then rotating the mold forcondensingthe moltenmetal at the outer portion of the castin 28. In adevice of the character described, in combinatioma'source of moltenmetal, a mold and means for rotating same,-and an ancillary limitedsource-of molten metal located between the axis and the periphery of thecasting intermediate the confines thereof.

29. In a casting apparatus, in combination with a source of moltenmetal, and'a moldand means for rotating the same,'a nd ancillary limitedsource of molten metal located between the axis and periphery of thecasting intermediate the confines thereof for compensatingior shrinkagein the casting after the pour from said first mentioned source iscompleted.

30. The method of making castings which includes introducingmolten metalinto a mold including an ancillary metal retaining means, rotating thecasting to impart centrifugal force against the periphery of the castingand augmenting the supply of'meta'l in direction of the centrifugalmotion with a force characteristic of the centrifugal force at pointswithin the limits of the body of the rotating casting. c

31. The method of making car wheel castings which includesintroducingmolten metal in a mold including an ancillary metalretainmgmeans, rotating the casting to impart centrifugal force against theperiphery of" the casting and augmenting the supply of metal from thesaid ancillary means, intermediate the axis and periphery of the castingat substantially the tread momentum.

'32.- In the process of molding castings in a rotating mold, the stepwhich includes introducing an. ancillary supply of molten metal near the(peripheral portion intermediate the axis an the body of the casting.

33. In the process of molding castings in 1 a rota-ting mold, the stepswhich comprise introdh'cing metal into the mold and forcing in anancillary supply of metal under pressure at points intermediate the axisand the periphery of the body of the casting.

34. In the a rotating mold,'the steps which comprise process-ofmoldingcastings in introducing metal-into the mold and forcing in an'ancillarysupply of metal under pressure substantially equal to that" induced bythe peripheral casting.

' JAMES CAREY DAVIS.

momentum off-the rotating

